After a standard system update you need to restart Firefox to make all the
necessary changes.

Details follow:

Several flaws were discovered in the browser engine of Firefox. If a user
were tricked into viewing a malicious site, a remote attacker could use
this to crash the browser or possibly run arbitrary code as the user
invoking the program. (CVE-2010-1208, CVE-2010-1209, CVE-2010-1211,
CVE-2010-1212)

An integer overflow was discovered in how Firefox processed plugin
parameters. An attacker could exploit this to crash the browser or possibly
run arbitrary code as the user invoking the program. (CVE-2010-1214)

A flaw was discovered in the Firefox JavaScript engine. If a user were
tricked into viewing a malicious site, a remote attacker code execute
arbitrary JavaScript with chrome privileges. (CVE-2010-1215)

An integer overflow was discovered in how Firefox processed CSS values. An
attacker could exploit this to crash the browser or possibly run arbitrary
code as the user invoking the program. (CVE-2010-2752)

An integer overflow was discovered in how Firefox interpreted the XUL
<tree> element. If a user were tricked into viewing a malicious site, a
remote attacker could use this to crash the browser or possibly run
arbitrary code as the user invoking the program. (CVE-2010-2753)

Aki Helin discovered that libpng did not properly handle certain malformed
PNG images. If a user were tricked into opening a crafted PNG file, an
attacker could cause a denial of service or possibly execute arbitrary code
with the privileges of the user invoking the program. (CVE-2010-1205)

Yosuke Hasegawa and Vladimir Vukicevic discovered that the same-origin
check in Firefox could be bypassed by utilizing the importScripts Web
Worker method. If a user were tricked into viewing a malicious website, an
attacker could exploit this to read data from other domains.
(CVE-2010-1213, CVE-2010-1207)

O. Andersen that Firefox did not properly map undefined positions within
certain 8 bit encodings. An attacker could utilize this to perform
cross-site scripting attacks. (CVE-2010-1210)

Michal Zalewski discovered flaws in how Firefox processed the HTTP 204 (no
content) code. An attacker could exploit this to spoof the location bar,
such as in a phishing attack. (CVE-2010-1206)

Jordi Chancel discovered that Firefox did not properly handle when a server
responds to an HTTPS request with plaintext and then processes JavaScript
history events. An attacker could exploit this to spoof the location bar,
such as in a phishing attack. (CVE-2010-2751)

Chris Evans discovered that Firefox did not properly process improper CSS
selectors. If a user were tricked into viewing a malicious website, an
attacker could exploit this to read data from other domains.
(CVE-2010-0654)

Soroush Dalili discovered that Firefox did not properly handle script error
output. An attacker could use this to access URL parameters from other
domains. (CVE-2010-2754)